Varnishes



Patented Nov. 27, 1934 UNITED STATES PATENT OFFICE SOLUBLE DRIER FOR PAINTS AND VARNISHES No Drawing. Application September 16, 1933, Serial No. 689,787

11 Claims.

This invention relates to driers for paints and varnishes and particularly to the so-called soluble drier class. The object of the invention is to furnish a drier of the stated type which shall have more desirable properties than driers employed heretofore, particularly in that they shall have a higher theoretical manganese value than the average drier heretofore and at least as high as any soluble drier employed in the past, and shall at the same time be more readily miscible and soluble in appropriate agents (e. g. naphtha) than previously known driers.

Driers employed heretofore have. usually been prepared from such organic acids as linoleic and abietic (resinic) acids. These acids are however unsaturated and at the same time possess such a high molecular Weight that the theoretical metal content thereof, which is the active constituent, is undesirably low. For instance the theoretical metal content of manganese linoleate is 9.0%. While some other driers have afforded a theoretical manganese content as high as 11%, these have offered the objections that they have been difficult to bring into solution or at least have required very awkward or dangerous procedures.

I have discovered that any one of the common so-called drying metals such as cobalt, manganose and the like combine to produce very satisfactory driers with the fatty acids of coconut oil or other equivalent saturated fatty acids, i. e. saturated fatty acids of low molecular Weight. These soluble driers possess all the desired properties of ready solubility (as in naphtha) at normal temperatures and have also the desired high metal content. For example the theoretical manganese content of the manganese-coconut acid compound hereof is about 11.5%.

According to the invention the soluble driers hereof may be made by combining with the fatty acids of coconut oil any suitable drying metal such as cobalt, copper, lead, manganese and zinc. Gxides or carbonates of these metals preferably are used. The fatty acids of the coconut oil are chiefly capric, lauric and myristic acids. These acids are saturated and are thereby distinguished from the unsaturated linoleic, abietic and other acids heretofore employed. The resultant mixed metal salts of these mixed coconut oil-acids, when in finished form so as to be free of Water and oil, possess a waxy consistency and are therefore easy to handle. The manganese-coconut oil drier for example, when stirred in cold napheasily converted into a clear solution by heating to the boiling point of water. lution does not reprecipitate for several hours after cooling and consequently may be added readily as a liquid drier to any of the paints and varnishes in the small amount required for these purposes. The resultant solution is stable. The products from the type of saturated fatty acids mentioned are less subject to spontaneous combustion and discoloring than the linoleates and resinates and contain no ingredients which are any more deleterious to paints and varnishes than the other soluble driers at present in use. The characteristics above indicated for the manganese-coconut acid drier apply equally well to the characteristics of the driers produced with the othermetals mentioned, all these driers having substantially the same desirable characteristics and high content of the active (metal) constituent.

As applied to a manganese-coconut acid drier, one desirable method of manufacture follows, the quantities and steps employed being substantially the same as for production of a drier with any of the other metals (correction of course being had for different molecular weights) The reaction is carried out in a closed kettle with suitable heating means, preferably a steam jacket, 2. reflux condenser communicating with the kettle through a trap from which water can be withdrawn while supernatant oil overflows back to the kettle. The kettle also contains a mechanical agitator.

The kettle is charged with 100 pounds (estimated for a mean molecular weight of 200) of coconut oil fatty acid, 400 to 500 pounds of naphthe. and such a quantity of cobalt carbonate as will contain 14.1 pounds of cobalt, the theoretical equivalent of 95 to 97 pounds of the fatty acid.

The charge is stirred and heated so as to cause the naphtha to vaporize into the reflux condenser. Carbon dioxide liberated in the reaction escapes from the head of the condenser. Water liberated in the reaction is vaporized and condensed with the naphtha, but is removed by trapping out while the naphtha condensate returns to The resultant soa 7 condition of maximum cobalt content by further evaporation preferably under vacuum.

The copper compound is made in the same way as above. using either normal or basic copper carbonate, in such quantity asto provide 15.3 pounds of copper, with the modifications that (1) due to the rapidity of the reaction the charge should be stirred for some time before heat is applied, and (2) due to the instability of the copper compound a more volatile grade of naphtha should be used and great care exercised to prevent local overheating, especially during the final reduction to solvent-free form.

The manganese compound is made the same way as the cobalt, using an amount of manganese carbonate to provide 13.2 pounds of manganese. The product is less stable than the cobalt compound but more so than the copper. Considerable care is required during the final reduction to solvent-free condition.

The lead and zinc compounds are made from the oxides inpreference to the carbonates, using quantities to provide 49.6 pounds of lead or 15.7 pounds of zinc. The procedure is the same as for the cobalt compound except that, in the case of lead, the solvent content of the charge can be reduced to 40 or 50 pounds in the kettle and still yield a product sui'ficiently fluid to handle when cooled to normal temperature. The lead and zinc compounds are very stable.

The digestion and the procedure above Outlined will ordinarily proceed for from one to four hours, the period varying according to conditions and even according to type of apparatus employed. Temperatures vary according to the drying metal being used; for instance, for the formation of copper fatty acid salts at an adequate rate, a temperature will be requiredabove about 250 F., preferably around 350, whereas manganese will require temperatures up to around 400 F. and cobalt up to around 450 or 500 F. These temperatures may be attained where naphtha is used as the solvent by employing a naphtha of greater or less volatility,,or a lighter nap-h the may be employed by operating under pressure. In addition to using oxides and carbonates of the drying metals mentioned, other compounds of these metals may be employed wherein the reaction products with the negative radicals will be eliminated in. the digestion and distillation. For example the hydroxides, sulfides and salts of weaker volatile acids such asthe acetates may be employed in some connections. In general a salt will be selected which is sufliciently stable and at the same time capable of insuring a sufficiently rapid rate of reaction. In case it is desired to avoid treatment in the presence of naphtha or similar solvent, an excess of fatty acid may be employed as a diluent and this excess eventually eliminated by distillation. m

It is to be understood that the above disclosures are not to be considered as limiting of the generic invention disclosed, inasmuch as many variations those skilled in the art.

I claim:

1. A drier for paints and varnishes in the form of the mixed salt of the fatty acids of coconut oil in combination with a drying metal.

2. An oil soluble drier for paints, varnishes and the like comprising the fatty acid salts of coconut oil produced by combining coconut oil fatty acids witha metal of the class consisting of cobalt, copper, lead, manganese and zinc.

3. A drier produced by combining a drying metal of the class consisting of cobalt, copper, lead, manganese and zinc with the fatty acids of coconutoil, the drier readily forming a fine suspension by stirring in cold naphtha, this suspension being readily converted into a clear solution by heating to the boiling point of water without reprecipitation for several hours after cooling.

4. As an article of manufacture, a manganesecoconut oil acid product produced by combining manganese with coconut oil acids, the product having a waxy consistency and readily forming a fine suspension by stirring in cold naphtha.

5. An oil soluble drier produced by the combination of coconut oil fatty acids with a drying metal of the class including cobalt, copper, lead,

manganese and zinc. I

6. An article according to claim 5 which readily forms a fine suspension by stirring in cold 5 naphtha, this suspension being converted into a clear solution by heating to the boiling point of water.

7. An oil soluble drier produced by combining a drying metal of the class consisting of cobalt, m

copper, lead, manganese and zinc with a mixture of capric, lauric and myristic acids, having a Waxy consistency and being readily miscible in cold naphtha and readily soluble in naphtha at the boiling point of water.

8. An oil soluble drier inthe form of a manganese-coconut compound resulting from the reaction of manganese with coconut oil acids, having a theoretical manganese content of at least 11%, having a waxy consistency and being read- 1 ily soluble to a clear solution in naphtha at the boiling point of water.

9. A method for the production of oil soluble driers comprising commingling with coconut oil fatty acids a compound of a drying metal of the 1 class consisting of cobalt, copper, lead, manganese and zinc, whose reaction products of its negative radical will be eliminated by distillation, and heating the mixture to a temperature and for a time. to complete the conversion to salts of the 1 fatty acids and to eliminate volatile products and constituents.

10. A method according to claim 9 wherein a relatively volatile solvent is added to the mixture and the reaction caused to take place in the pres- 1 ence of the solvent, and removing at least a part of the solvent by distillation.

11. A method according to claimv 9 wherein the metallic compound is used in amount less than the theoretical amount required for conversion 1 of the fatty acids.

ROBERT A. DUNHAM. 

